Optical measurements of pH using fluorescence lifetimes and phase-modulation fluorometry
نویسندگان
چکیده
منابع مشابه
Confocal pH imaging of microscopic specimens using fluorescence lifetimes and phase fluorometry: influence of parameter choice on system performance.
We investigate the performance of confocal pH imaging when using phase fluorometry and fluorophores with pH-dependent lifetimes. In these experiments, the specimen is illuminated by a laser beam, whose intensity is sinusoidally modulated. The lifetime-dependent phase shift in the fluorescent signal is detected by a lock-in amplifier, and converted into a pH value through a calibration procedure...
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A new gated form of phase fluorometry for measuring lifetimes is presented. The technique uses a square-wave excitation and gates the detector on only during the off period of the excitation. Using a long-lived sample, this eliminates or reduces errors from scattered light and short-lived fluorescences. Using a square-wave modulated excitation source with a 50% duty cycle, traditional data trea...
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The analysis of the fluorescence decay using discrete exponential components assumes that a small number of species is present. In the absence of a definite kinetic model or when a large number of species is present, the exponential analysis underestimates the uncertainty of the recovered lifetime values. A different approach to determine the lifetime of a population of molecules is the use of ...
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General Aspects Determination of characteristic fluorescence parameters i.e. spectral properties, quantum yields, polarizations, and lifetimes, is important in the study of excited states of atoms, molecules, and crystals and also for diagnostic purposes in the physical, chemical, biological, and medical sciences. The appeal of fluorescence methodologies lies in their intrinsic sensitivity and ...
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We report the first time-resolved fluorescence emission spectra and time-resolved fluorescence anisotropies obtained using frequency-domain fluorescence spectroscopy. We examined the fluorophore p-2-toluidinyl-6-naphthalenesulfonic acid (TNS) in viscous solvents and bound to the heme site of apomyoglobin using multifrequency phase fluorometers. Fluorescence phase shift and modulation data were ...
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ژورنال
عنوان ژورنال: Analytical Chemistry
سال: 1993
ISSN: 0003-2700,1520-6882
DOI: 10.1021/ac00061a007